With his request for congressional authorization for strikes on Syria faltering, President Barack Obama announced he would make the case to the nation on Tuesday from the White House.

Speaking at a press conference from the G-20 summit in Russia, the president said he would continue trying to convince a skeptical American public and Congress of the need to act.

“I will make the best case that I can,” he said.

He also came the closest yet to saying he would not strike Syria without Congress’ approval, reiterating that the move was not “symbolic.” He said he could not claim that Syria’s use of chemical weapons on its own people was an imminent threat to the United States or its allies.

“This wasn’t even a situation like Libya, where, you know, you’ve got troops rolling towards Benghazi and you have a concern about time, in terms of saving somebody right away,” he said.

But he stopped short of saying that he wouldn’t strike under repeated questioning.

“I’m not going to engage in parlor games now ... about whether or not it’s going to pass, when I’m talking substantively to Congress about why this is important and talking to American people about why this is important,” he said.

Obama also said he was not eager to take military action.

“I was elected to end wars and not start ‘em. I’ve spent the last four years to do everything I can to reduce our reliance on military power,” he said. “But what I also know is there are times where we have to make hard choices if we’re going to stand up for the things that we care about.”

Obama said he is not surprised by the opposition in Congress.

“I knew this was going to be a heavy lift,” he said. He noted he had his own polling operations and knew the reluctance of the American people who have been through a decade of war, including in his own party.

“My goal is to maintain the international norm on banning chemical weapons. I want that enforcement to be real, I want it to be serious. I want people to understand that gassing innocent people, delivering chemical weapons against children is something we don’t do. . . . We’ve got to stand up for that principle.”

As for members of Congress, Obama said that it’s conceivable he could fail to convince a majority of the public of the need for action, and in that case it would be up to lawmakers to decide what they think is best for the country, even if it’s unpopular.

He said that intervening in Kosovo was unpopular at the time, but was the right thing to do. He also referenced Rwanda, saying that if that country’s genocide was taking place now, intervening would be unpopular there too.

Asked what he might do if the Senate and House split on the authorization, Obama said he didn’t want to “jump the gun and speculate because right now, I’m working to get as much support as possible.”

However, White House Deputy National Security Adviser Tony Blinken told NPR this morning that the president would not likely act without Congress’ approval.

“The president, of course, has the authorization to act, but it’s neither his desire nor his intention to use that authority absent Congress backing him,” Blinken said.